Tuning applications that use the Java Persistence API

Configuring OpenJPA caching to improve performance
The OpenJPA implementation gives you the option of storing frequently used data in the memory to improve performance. OpenJPA provides concurrent data and concurrent query caches that support applications to save persistent object data and query results in memory to share among threads and for use in future queries.
JPA system properties
In addition to the settings that are accessible from the administrative console, you can set Java Persistence API (JPA) system properties using command-line scripting.
Configuring WSJPA ObjectCache to improve performance
The WebSphere® Java™ Persistence API (WSJPA) extension to OpenJPA provides a read-only object cache that can improve performance in certain use cases.
Pre-loading the WSJPA ObjectCache automatically
The WebSphere Java Persistence API (WSJPA) extension to OpenJPA provides a read-only ObjectCache that can improve performance in certain use cases. By default, the data in the cache is loaded in a lazy method, which means that individual entities are loaded into memory when they are requested by an application. If you want to load all the entities from the beginning, though, you can configure the application server to preload all of the entities from the database that are configured in the ObjectCache. Pre-loading the ObjectCache will allow you to cache entities that would otherwise be restricted when if you load the ObjectCache through the lazy method.